JP6891142B2 - Metallic film for capacitor elements and metallized film capacitors using it - Google Patents

Description

The present invention relates to a metallized film for a capacitor element and a metallized film capacitor using the same, and relates to an improvement of a vapor deposition pattern of the metallized film.

In the technical field of metallized film capacitors used in hybrid vehicles (HV), electric vehicles (EV), fuel cell vehicles (FCV) and industrial machinery, the thickness of the dielectric film is to reduce the size, weight and cost. Is required to be thin. In order to reduce the thickness of the dielectric film, it is required to improve the withstand voltage performance, and as a means for that purpose, the material is improved and the vapor deposition pattern of the vapor deposition electrode formed on the dielectric film is improved.

The metallized film capacitor restores the insulation by scattering the deposited metal around it due to the dielectric breakdown of the metallized film (self-healing function). Since the surrounding vapor-film electrode is scattered and disappears, the progress of dielectric breakdown stops there and the insulation is restored. However, at high temperatures and high voltages where the number of dielectric breakdowns increases, the self-healing function cannot be sufficiently obtained, and the capacitor may fall into a short mode. That is, in a metallized film capacitor in which a metallized film having a vapor-deposited metal film is laminated and wound on a dielectric film, if the vapor-deposited metal is not sufficiently scattered, the vapor-deposited metal is sufficiently scattered through the defective portion of the dielectric film. Two layers of vapor-deposited metals facing each other conduct with each other, resulting in a short circuit.

Therefore, a safety mechanism consisting of a plurality of split electrodes and a fuse was devised. When the split electrode is formed in the metallized film, even if dielectric breakdown occurs beyond the self-healing function of the metallized film, current flows from the surrounding split electrode to the split electrode that has undergone dielectric breakdown, and the deposited metal of the fuse is formed. Due to the scattered fuse operation, the split electrode that has undergone dielectric breakdown is separated from the other split electrodes to restore the insulation, and high safety can be ensured.

On the other hand, the effective electrode area that contributes to capacity development is reduced by the fuse operation.
Therefore, the withstand voltage performance is improved by reducing the area of the divided electrode. One of the methods is a pattern technique in which a set of a large-area electrode row region and a small-area electrode row region is alternately repeated in the width direction of a dielectric film (hereinafter, referred to as “film width direction”) (for example, Patent Document 1). reference).

Japanese Unexamined Patent Publication No. 2016-134420

Here, the subdivision of the split electrode will be described with reference to FIG. FIG. 8A shows the split electrode of the first conventional example, and has a relatively large split electrode area. On the other hand, FIG. 8B shows the split electrode of the second conventional example, and the area of the split electrode is about half that of the case of FIG. 8A.

In FIG. 8A, one split electrode 5 is formed by being sandwiched between a pair of left and right insulating slits 4 and 4. In FIG. 8B, by adding a third insulating slit 4a having substantially the same shape as the pair of left and right insulating slits 4 and 4 at the center of the split electrode 5 in FIG. A pair of left and right subdivided small electrodes 5b and 5b corresponding to the divided ones are formed. The area of one subdivided small electrode 5b in FIG. 8 (b) is approximately half the area of the divided electrode 5 in FIG. 8 (a).

However, in FIG. 8B, if clearing (evaporation scattering / disappearance of the metal vapor deposition film due to dielectric breakdown) occurs starting from the position indicated by P on the right subdivided small electrode 5b, the rated voltage is high. When the voltage is large and the current flowing into the subdivided small electrode 5b on the right side is large, the metal vapor deposition film of the fuse portion evaporates and scatters, and the entire (total surface integration) of the subdivided small electrode 5b on the right side forms a capacitance. Loss of functionality (see fill). That is, regarding the size of the effective electrode area that disappears due to dielectric breakdown that occurs between the two vapor-deposited electrodes that face each other with the dielectric film in between, in the case of the subdivided small electrode 5b of FIG. 8 (b), FIG. 8 ( It is about half that of the split electrode 5 in a), and the decrease in the capacitance of the capacitor can be suppressed, but the decrease in the capacitance of the capacitor is also suppressed in the second conventional example of FIG. 8 (b). It can be said that there is still room for improvement regarding the suppression of.

Further, as described above, the smaller the area of the split electrode, the more the capacitance decrease due to the fuse operation can be suppressed. On the other hand, if the split electrode is subdivided too much, the effective electrode of the metallized film due to the formation of the insulating slit is formed. The area is reduced and the capacity of the capacitor is reduced.

Further, if the area of the split electrode is reduced, the number of fuses increases, but since the fuse portion has a higher resistance than that of the split electrode, the heat generation of the capacitor increases. Such an increase in self-heating causes a decrease in withstand voltage performance and safety performance. In particular, the temperature of the center of the capacitor element formed by winding or laminating a metallized film rises sharply due to self-heating, and the withstand voltage performance and safety performance are deteriorated compared to other parts.

Further, as the rated voltage increases, the width of the insulating slit increases, which causes a problem that the effective electrode area further decreases. As the rated voltage of the metallized film capacitor increases, the width of the insulating slit becomes larger and the effective electrode area becomes smaller, and the capacitance of the capacitor decreases. Further, the reduction of the capacitance of the capacitor progresses with the operation of the fuse during use (scattering of vapor-deposited metal), which adversely affects the life of the capacitor.

The present invention was created in view of such circumstances, and an object of the present invention is to improve the withstand voltage performance while suppressing the reduction of the effective electrode area and the loss of the capacitance forming function to improve the capacitor life. There is.

The present invention solves the above problems by taking the following measures.

The metallized film for a capacitor element according to the present invention
With a dielectric film in which the vapor deposition electrodes are formed on at least one side,
The vapor-deposited electrode is developed in a small area electrode row region developed in a relative small area division state along the film longitudinal direction of the dielectric and in a continuous state or a relative large area division state along the film longitudinal direction. The set with the large-area electrode row region to be formed is repeatedly arranged along the film width direction of the dielectric.
The small-area electrode row region is partitioned into each divided electrode by a continuous first insulating slit extending in the film width direction and having no break in the middle portion.
Wherein each of the divided electrodes,
It is electrically connected to the large area electrode row region at the end of the first insulating slit in the film width direction via the first fuse.
Further, it is partitioned into a pair of subdivided small electrodes facing each other in the film longitudinal direction by a second insulating slit extending in the film width direction at the intermediate portion in the film longitudinal direction.
The pair of subdivided small electrodes are electrically connected to each other via a second fuse at a cut in the middle of the second insulating slit.
Each subdivided small electrode is divided into a pair of unit electrodes adjacent areas in the width direction of the film, their pair of unit electrodes regions communicate with each other,
The second insulating slit has one portion and the other portion separated from each other with the second fuse, which is the cut, interposed therebetween.
Of the pair of subdivided small electrodes facing each other in the longitudinal direction of the film, the first subdivided small electrode on one side in the longitudinal direction of the film is one portion of the second insulating slit and one side in the longitudinal direction of the film. A first unit electrode region sandwiched between the first insulating slits located in, and the other portion of the second insulating slit and the first insulating slit located on one side in the longitudinal direction of the film. It is a second unit electrode region sandwiched between
Of the pair of subdivided small electrodes facing each other in the longitudinal direction of the film, the second subdivided small electrode on the other side in the longitudinal direction of the film is the one portion of the second insulating slit and the other side in the longitudinal direction of the film. A third unit electrode region sandwiched between the first insulating slits located in, and the other portion of the second insulating slit and the first insulating slit located on the other side in the longitudinal direction of the film. It is a fourth unit electrode region sandwiched between
Each of the first to fourth unit electrode regions is electrically connected to the large area electrode row region via the first fuse .

In the above configuration, the pair of first insulating slits and the second insulating slit between them have the same directionality, and a second slit is arranged in the middle of the second insulating slit. Since the fuse is formed, each subdivided small electrode is partitioned into a plurality of unit electrode regions. The unit electrode regions adjacent to each other in the film width direction are continuous with each other. That is, although the vapor deposition electrodes are a series of electrodes, they are independent of each other in the expression of the clearing function. In each unit electrode region, the clearing function there is independently expressed independently of the other unit electrode regions.

The details are as follows. A pair of subdivided small electrodes in the longitudinal direction of the film will be referred to as a first subdivided small electrode and a second subdivided small electrode. In any of the subdivided small electrodes, the one located on one side of the plurality of unit electrode regions in the film width direction is called the unit electrode region on one side, and the one located on the other side in the film width direction is called the other. It will be referred to as the unit electrode region on the side.

The path through which the current flowing from the first fuse on one side of the first subdivided small electrode passes is the path leading to the first fuse on the other side of the first subdivided small electrode, and the second insulation. A path through a second fuse provided on the slit to an adjacent second subdivided small electrode and further to a first fuse on the other side of the second subdivided small electrode, and a second subdivision. It is a path leading to the first fuse on one side of the small electrode. That is, there are three routes.

Further, the paths through which the current flowing from the first fuse on one side of the second subdivided small electrode passes are the path leading to the first fuse on the other side of the second subdivided small electrode and the second. A path through a second fuse provided on the insulating slit of the above to reach the adjacent first subdivided small electrode and further to the first fuse on the other side of the first subdivided small electrode, and a first It is a path leading to the first fuse on one side of the subdivided small electrode. This is also three routes. The above is an example, and is an example in which one second fuse is provided on the second insulating slit. The more second fuses, the more current paths.

It is assumed that dielectric breakdown occurs in any one of the plurality of unit electrode regions formed in one divided electrode. At this time, the area of the area where the clearing is performed is, in principle, limited to one unit electrode area where the dielectric breakdown has occurred. That is, the remaining plurality of unit electrode regions are preserved without causing clearing. A large current inrush occurs due to dielectric breakdown, and most of it concentrates on the unit electrode region (1) of dielectric breakdown and clears the unit electrode region, as described above. There are many current paths, and the current flows separately in each path. That is, since there are many escape paths for the incoming current, a plurality of unit electrode regions other than the dielectric breakdown unit electrode region escape clearing and are preserved as normal vapor-deposited electrodes.

As described above, since the area of the electrode that is divided and invalidated by the scattering of the vapor-deposited metal when dielectric breakdown occurs becomes smaller, the reduction of the effective electrode area and the disappearance of the capacitance forming function are suppressed to improve the capacitor life. At the same time, it is possible to improve the withstand voltage performance.

Moreover, according to the present invention, since the unit electrode region is formed without additionally forming a new insulating slit, it is possible to avoid a decrease in the effective electrode area due to the formation of the insulating slit. Therefore, it is possible to suppress the decrease in the effective electrode area due to the increase in the insulating slit width due to the increase in voltage as much as possible, and to reduce the effective electrode area disappearance rate while improving the withstand voltage performance. Further, by providing a fuse in the middle of the second insulating slit, it is possible to prevent an increase in the fuse (high resistance part) and prevent the capacitor from increasing as compared with the case where the insulating slit is formed in the longitudinal direction of the film and the fuses are provided at both ends thereof. Fever can be suppressed.

In the above configuration, the first insulating slit and the second insulating slit are adjacent to each other while the second insulating slit is arranged between each pair of adjacent first insulating slits. The first insulating slit is arranged between each pair of the second insulating slits, and the first insulating slit and the second insulating slit are skipped along the longitudinal direction of the film. It is preferable that they are arranged alternately with. By regularly arranging the subdivided small electrodes, it is possible to make the properties of the metallized film uniform over the entire surface, which is effective in extending the life of the metallized film capacitor.

Further, the metallized film capacitor according to the present invention is a metallized film capacitor formed by superimposing two metallized films for any of the above-mentioned capacitor elements to form a pair of metallized films. All of the large-area electrode row regions of one of the metallized films face the subdivided small electrodes of the other metallized film.

According to the present invention, the area of the electrode that is divided and invalidated by the scattering of the vapor-deposited metal when dielectric breakdown occurs becomes smaller, so that the reduction of the effective electrode area and the disappearance of the capacitance forming function are suppressed to extend the life of the capacitor. While improving, the withstand voltage performance can be improved.

Plan view and cross-sectional view showing the structure of the metallized film for the capacitor element in the embodiment of the present invention. A plan view showing a part of the metallized film in the embodiment of the present invention in an enlarged manner. A plan view showing an enlarged view of the divided electrode portion in the embodiment of the present invention. Top view showing the metallized film of two stacked sheets in the Example of this invention. Perspective view of a capacitor element using a metallized film according to an embodiment of the present invention. Explanatory drawing of operation of metallized film which concerns on Example of this invention Schematic diagram of dielectric breakdown / clearing operation of the metallized film according to the embodiment of the present invention. Top view showing the divided electrodes of the conventional example

Hereinafter, the metallized film for the capacitor element of the present invention having the above configuration will be described in detail in detail at the level of specific examples.

1 (a) is a plan view showing the configuration of a metallized film for a capacitor element in an embodiment of the present invention, FIG. 1 (b) is a cross-sectional view thereof, and FIG. 2 is an enlarged view of a part of the metallized film. The plan view and FIG. 3 are an enlarged plan view showing the divided electrode portion.

In FIGS. 1 and 2, 1 is a metallized film, 2 is a dielectric film (shown in FIG. 1 in which a part of the vapor deposition electrode is peeled off), and 3 is vapor deposition made of a metal such as aluminum, zinc or an alloy thereof. Electrode 4 is a first insulating slit, 4b is a second insulating slit, 4c is a linear insulating slit, 5B is a split electrode, 5b is a subdivided small electrode, 6 is a first fuse, and 6b is a second. Fuse, 7 is an electrode lead-out connection portion, 8 is an insulation margin, A1 and A2 are large-area electrode row regions forming a part of the vapor-deposited electrode 3, and B1 and B2 are small-area electrodes forming the remaining part of the vapor-deposited electrode 3. The row region, a1 is the first medium-area electrode, and a2 is the second medium-area electrode.

The metallized film 1 is formed by forming a pattern of a vapor-deposited electrode 3 on the surface of a dielectric film 2. The vapor-deposited electrode 3 is composed of a set of two rows of large-area electrode row regions and small-area electrode row regions (A1, B1) and (A2, B2). A1 is a large-area electrode row region in the first row, B1 is a small-area electrode row region in the first row, and these are a set of a large-area electrode row region and a small-area electrode row region in the first row (A1, B1). To configure. A2 is the large area electrode row region of the second row, B2 is the small area electrode row region of the second row, and these are a set of the large area electrode row region and the small area electrode row region of the second row (A2, B2). To configure. In this example, the repeating arrangement of the set of the large-area electrode row region and the small-area electrode row region is two rows.

The large-area electrode row region A1 of the first row includes an electrode lead-out connection portion 7 for connecting a metal sprayed electrode (metallikon) at one end edge of the film width direction Y of the metallized film 1. The electrode lead-out connection portion 7 is a region (a laterally elongated conductor region outside the broken line in FIG. 1) that is continuously developed along the film longitudinal direction X at one end edge of the film width direction Y. It is integrally connected to the large-area electrode row region A1 of the first row. As shown in FIG. 1 (b), the electrode lead-out connection portion 7 has an electrode thickness that is thicker than that of other regions of the vapor-deposited electrode 3. Therefore, the connection reliability between the electrode lead-out connection portion 7 and the electrode lead-out portion (metallikon) is high. The thick electrode lead-out connection portion 7 is referred to as a heavy edge portion, and the other thin region of the vapor deposition electrode 3 is referred to as an active portion.

In the small area electrode row region B1 of the first row, the first insulating slit 4 is formed in a so-called Müller-rear shape. That is, the first insulating slit 4 has a shape having inward arrow blades at both ends of a line segment having a predetermined length. In the small area electrode row region B2 of the second row, the first insulating slit 4 is formed in a Y shape (a shape in which the inward arrow blade on one end side is missing in the Muller-rear shape). In the small area electrode row region B2 of the second row, the first insulating slit 4 is connected to the insulating margin 8 at the other end edge of the metallized film 1 in the film width direction Y. The insulation margin 8 is a laterally elongated insulating region that is continuously developed in the film longitudinal direction X at the other end edge of the dielectric film 2 in the film width direction Y. Other configurations are the same as in the first row.

The large-area electrode row region Ai (i = 1, 2) is a region continuously developed along the film longitudinal direction X. The small-area electrode row region Bi (i = 1, 2) is divided and formed by a Muller-rear-shaped or Y-shaped first insulating slit 4 arranged at predetermined intervals in the film longitudinal direction X as its basic configuration. This is a region having a plurality of divided electrodes 5B. Then, two sets of the large-area electrode row region and the small-area electrode row region (Ai, Bi) are repeatedly arranged along the film width direction Y. Further, in the small area electrode row region B1 of the first row, each divided electrode 5B as a basic configuration thereof is a first fuse 6 made of a metal vapor deposition film at a cut of the first insulating slit 4 on both sides in the film width direction Y. , 6 are electrically connected to the large-area electrode row regions A1 and A2 on both sides. In the small area electrode row region B2 of the second row, each divided electrode 5B as its basic configuration has a first fuse 6 made of a metal vapor deposition film at a cut of the first insulating slit 4 on one side in the film width direction Y. It is electrically connected to the large-area electrode row region A2 on one side of the intervening state.

Then, the vapor-deposited electrode 3 composed of two sets of the large-area electrode row region and the small-area electrode row region as described above is formed on at least one side of the dielectric film 2 to form the metallized film 1.

Further, the embodiment of the present invention adopts the following configuration. Hereinafter, the characteristic configurations (second insulating slit 4b and second fuse 6b) in this embodiment will be described.

That is, the pattern in each small area electrode row region Bi (i = 1, 2) is based on a plurality of divided electrodes 5B partitioned by a pair of first insulating slits 4 and 4 facing each other in the film longitudinal direction X. Above, in each of the divided electrodes 5B, a second insulating slit 4b is further arranged in the middle portion in the longitudinal direction X of the film, and each divided electrode 5B is partitioned into a pair of subdivided small electrodes 5b and 5b. Further, the pair of subdivided small electrodes 5b and 5b are electrically connected to each other through a second fuse 6b made of a metal vapor deposition film formed in the middle of the film width direction Y of the second insulating slit 4b. It is connected to the. As a result of the above, the subdivided small electrodes 5b and 5b communicate with each other in the film width direction Y and are partitioned into a plurality of unit electrode regions 5c ... Each having a clearing function (self-healing function) independently. Conversely, two unit electrode regions 5c and 5c adjacent to each other in the film width direction Y constitute one subdivided small electrode 5b. Then, two subdivided small electrodes 5b and 5b adjacent to each other in the film longitudinal direction X constitute one divided electrode 5B.

In the relationship between the first insulating slit 4 and the second insulating slit 4b, a second insulating slit 4b is arranged between each pair of adjacent first insulating slits 4, 4 and adjacent to each other. The first insulating slit 4 is arranged between the pair of second insulating slits 4b, 4b. That is, the first insulating slits 4 and the second insulating slits 4b are alternately arranged along the film longitudinal direction X with one skipped state.

Further, in the case of this embodiment, since only one second fuse 6b is formed at the center of the second insulating slit 4b, the number of unit electrode regions 5c per divided electrode 5B is four. The number of the second fuses 6b formed in one second insulating slit 4b is not limited to one, and may be any number. In the case of two, the number of unit electrode regions 5c is six, and in the case of three, the number of unit electrode regions 5c is eight (not shown).

A plurality of large-area electrode row regions A1 and A2 are in a relatively large-area divided state with a pitch larger than the pitch of the divided electrodes 5B of the small-area electrode row regions B1 and B2 along the film longitudinal direction X, respectively. It is partitioned by a dividing electrode. These are the first medium-area electrode a1 and the second medium-area electrode a2.

Specifically, the large-area electrode row region A1 of the first row is partitioned in the film longitudinal direction X by a linear insulating slit 4c extending in the film width direction Y, but the pitch of the linear insulating slit 4c is a small area. It corresponds to 4 pitches of the first insulating slit 4 in the electrode row region B1. Further, the pitch of the linear insulating slit 4c for partitioning the large area electrode row region A2 in the second row corresponds to 8 pitches of the linear insulating slit 4c. The linear insulating slit 4c is formed as an extension line of the central line segment of the first insulating slit 4 (note that the present invention is not limited to this).

The first medium-area electrode a1 formed by being partitioned by a pair of adjacent linear insulating slits 4c and 4c in the large-area electrode row region A1 of the first row is in a state of repeating along the film longitudinal direction X. It is arranged. Further, the second medium-area electrode a2 formed by being partitioned by a pair of adjacent linear insulating slits 4c and 4c in the large-area electrode row region A2 of the second row is also repeated along the film longitudinal direction X. Arranged in the state. The area of each of the first medium-area electrode a1 and the second medium-area electrode a2 is 4 to 16 times the area of one subdivided small electrode 5b (combined two unit electrode regions 5c and 5c). Is preferable. By setting the area in this way, the amount of current flowing in and out can be optimized, and the withstand voltage and safety can be satisfactorily improved.

It should be noted that one or both of the large-area electrode row regions A1 and A2 may be continuous regions in the film longitudinal direction X without providing the linear insulating slits 4c.

Two sheets of the metallized film 1 formed by forming the vapor deposition electrode 3 on the dielectric film 2 as described above are prepared, and as shown in FIG. 4, the metallized films 1 and 1 of both sheets are inverted by 180 °. In this state, the electrode lead-out connection portion 7 of one metallized film is superposed on the upper and lower two layers so as not to overlap with the vapor deposition electrode of the other metallized film. The large-area electrode row region A1 in the first row along the side edge of the upper metallized film 1 faces the small-area electrode row region B2 in the second row of the lower metallized film 1 immediately below the large-area electrode row region A1. The electrode lead-out connection portion 7 faces the insulation margin 8. The second-row large-area electrode row region A2 of the upper metallized film 1 faces the first-row small-area electrode row region B1 of the lower metallized film 1. Further, the small area electrode row region B1 in the first row of the upper metallized film 1 faces the large area electrode row region A2 of the second row in the lower metallized film 1. The large-area electrode row region A1 of the first row on the side edge of the lower metallized film 1 faces directly below the small-area electrode row region B2 of the second row of the upper metallized film 1. The insulation margin 8 faces the electrode lead-out connection portion 7. In short, the small area electrode row region in one metallized film faces the large area electrode row region in the other metallized film.

Here, if the large-area electrode row region of one metallized film and the large-area electrode row region of the other metallized film face each other, short-circuit fracture may occur. It is preferred that all face a small area electrode row region (a pair of subdivided small electrodes) in the other metallized film. From the viewpoint of avoiding the large-area electrode row region of one metallized film and the large-area electrode row region of the other metallized film facing each other, all of the large-area electrode row regions of one metallized film. Should face the subdivided small electrodes (one of the pair of subdivided small electrodes) in the other metallized film.

As described above, in a state where the upper metallized film 1 and the lower metallized film 1 are overlapped with each other, as shown in FIG. 5, the outer peripheral film of the winding core 9 is wound in multiple layers, and the outermost layer is an exterior film. After winding No. 10, the film is flattened into an elongated oval shape (flattening ratio is 0.7 or more) by pressing as shown to obtain a metallized film multilayer body 11. Further, electrode lead-out portions (metallikons) 12 and 12 are formed by metal spraying at both ends of the metallized film multilayer body 11 in the axial direction to obtain a highly flat metallized film capacitor element C. The electrode lead-out portions 12 and 12 are electrically connected to the electrode lead-out connection portions 7 and 7 on both sides in the axial direction.

There is also a type of capacitor element in which two short metallized films 1 and 1 are laminated instead of winding the two long metallized films 1 and 1 as described above.

In the metallized film capacitor of the present embodiment configured as described above, the pair of first insulating slits 4 and 4 forming the divided electrodes 5B of the small area electrode row regions B1 and B2 have a film width in the main axis direction. The direction is Y. Further, the main axis direction of the second insulating slit 4b between the pair of the first insulating slits 4 and 4 is the film width direction Y. That is, the pair of first insulating slits 4 and 4 and the second insulating slit 4b have the same directionality. Further, one divided electrode 5B is partitioned by a second insulating slit 4b into a pair of subdivided small electrodes 5b and 5b having the same shape and the same size. In addition, a slit cut is arranged in the middle of the second insulating slit 4b to form a second fuse 6b, and a pair of subdivided small electrodes 5b and 5b are electrically operated in the film longitudinal direction X inside the dividing electrode 5B. Is connected.

As a result of the above, each subdivided small electrode 5b, 5b is partitioned into two unit electrode regions 5c, 5c, respectively. Here, the unit electrode region means that clearing occurs when dielectric breakdown occurs between the opposing metallized films 1 and 1 inside the unit electrode region, and the clearing is not applied to the adjacent unit electrode region 5c. It is an area that has a clearing function by itself.

The unit electrode regions 5c and 5c adjacent to each other in the film width direction Y are continuous with each other. That is, although the vapor deposition electrodes are a series of electrodes, they are independent of each other in the expression of the clearing function.

Here, the longitudinal direction of the film pair subdivision small electrode 5b in the X, the first subdivision small electrodes 5b 5b respectively ₁ (left side (one side)), the second subdivision small electrode 5b ₂ (right side (the other Side)) ). Further, in the first subdivided small electrode 5b ₁ , the upper one of the two unit electrode regions 5c and 5c in the film width direction Y is referred to as the _first unit electrode region 5c 1 located on the upper left side. The lower one will be referred to as the _second unit electrode region 5c 2 located on the lower left side. Further, in the second subdivided small electrode 5b ₂ , the upper side of the two unit electrode regions 5c and 5c in the film width direction Y is referred to as a _third unit electrode region 5c 3 located on the upper right side. The lower one will be referred to as the _fourth unit electrode region 5c 4 located on the lower right side.

The first unit electrode region 5c ₁ located on the upper left side, the second unit electrode region 5c ₂ located on the lower left side, the third unit electrode region 5c ₃ located on the upper right side, and the position on the lower right side . The clearing functions of the fourth unit electrode region 5c ₄ are independent of each other, and the clearing function generated in one unit electrode region does not spread to any of the other unit electrode regions. That is, the clearing function is self-contained within each unit electrode region. The clearing function there is independently expressed independently of the other unit electrode regions 5c ....

As shown in FIG. 6A, the destination where the current flowing from the upper first fuse 6 in the first (left side) subdivided small electrode 5b ₁ flows out is the first subdivided small electrode 5b _{1 The region where the current flows through the path (i 1} ) of the lower first fuse 6 and the second fuse 6b formed on the second insulating slit 4b, that is, the first subdivided small electrode. _{The path (i 2} ) of the lower first fuse 6 in the second (right) subdivided small electrode 5b ₂ adjacent to 5b ₁ and the upper first fuse in the second subdivided small electrode 5b _2. It is the route of 6 (i ₃ ). That is, there are three paths, a linear path i ₁ , a crank-shaped path i ₂ (tangent curved), and a U-shaped path i _3.

Further, as shown in FIG. 6B, the destination where the current flowing from the upper first fuse 6 in the second (right side) subdivided small electrode 5b ₂ flows out is the second subdivided small electrode. the path of the first fuse 6 in the lower (i ₄₎ in 5b _2, areas where flowing through the second fuse 6b, namely the first (left side adjacent to the second subdivision small electrodes 5b ₂ out with the path of the first fuse 6 in the lower (i _5), and the path of the first fuse 6 of the upper in the first subdivision small electrode 5b ₁ (i ₆₎ in subdividing small electrode 5b ₁₎ is there. There are also three paths, a linear path i ₄ , a crank-shaped path i ₅ (tangent curved), and a U-shaped path i _6.

Moreover, previous to the current flowing from the first fuse 6 lower in granularity small electrode 5b ₁ of the first (left side) flows out, the upper side of the first fuse in its first subdivision small electrodes 5b ₁ 6 paths ( _{current in the direction opposite to i 1} ; hereinafter referred to as "anti-i ₁ "; the same applies hereinafter) and the adjacent second (right) subdivided small electrode 5b where the current flows through the second fuse 6b. an upper path of the first fuse 6 in ₂ (anti-i _5), a path of the first fuse 6 in the lower (i ₈₎ (Fig. 7). Also, ahead of the current flowing from the first fuse 6 of the lower side in the second subdivision small electrodes 5b ₂ flows out, the path of the first fuse 6 of the upper side in the second subdivision small electrodes 5b ₂ (Anti-i _{4 ) and the path (anti-i 2} ) of the upper first fuse 6 in the adjacent first subdivided small electrode 5b ₁ where it flows in through the second fuse 6b and the lower first. It is the path (i ₇ ) of the fuse 6 of 1 (FIG. 7).

Considering the outbound route and the inbound route, there are a total of 12 routes, which is significantly more than the 4 routes in the conventional example.

It is assumed that dielectric breakdown occurs in any one of the four unit electrode regions 5c formed in one divided electrode 5B. Clearing occurs only in the unit electrode region 5c where the dielectric breakdown has occurred, and the clearing does not spread to the remaining unit electrode regions 5c ... The reason is as follows.

Now, as shown in FIG. 7A, the unit electrode region 5c in which the dielectric breakdown has occurred is defined as the third unit electrode region 5c ₃ located on the upper right side. Since the resistance value of the dielectric breakdown portion P is significantly reduced, a large current suddenly flows in from the periphery, and clearing is performed by evaporation and scattering of the metal vapor deposition film. The inflow routes at that time are i ₄ , anti-i ₄ , i ₃ , and anti-i ₅ . Here, the path i ₄ is a current path going from the top to the bottom in the figure, and the anti-i ₄ is a current path going in the direction opposite to the _{path i 4.} When the clearing is finished, the large current disappears and it returns to the steady state.

In the above process, even if the large current flowing into the dielectric breakdown point P becomes excessive, the excess current is passed through the upper first fuse 6 and the lower first fuse 6 to form a large area electrode array. It can be escaped to the area A1.

That is, as shown in FIG. 7 (b), the current flowing from the lower first fuse 6 in the second (right side) subdivided small electrode 5 b ₂ passes through the second fuse 6 b and further passes through the second fuse 6 b . 1 (Left side) Subdivided small electrode 5 b ₁ External large area electrode via the upper first fuse 6 (anti-i ₂ path) or the lower first fuse 6 (i _{7 path)} It flows out to the column areas A1 and A2.

Further, the current flowing from the upper first fuse 6 in the first (left side) subdivided small electrode 5 b ₁ passes through the second fuse 6 b and is further passed through the second (right side) subdivided small electrode 5 b 1. first fuse 6 in the _second lower via (route i ₂₎ flows out to the outside of the large-area electrode array region A2.

Further, the current flowing from the lower first fuse 6 in the first (left side) subdivided small electrode 5 b ₁ passes through the second fuse 6 b and is further passed through the second (right side) subdivided small electrode 5 It flows out to the external large-area electrode row region A2 through the first fuse 6 ( _{path of i 8} ) on the lower side of b _2.

In this way, the excess current is dispersed and becomes a small current that flows out to the large-area electrode row regions A1 and A2. Therefore, the clearing inside the split electrode 5 is one unit electrode including the dielectric breakdown portion P. Except for region 5c ₃ , it does not occur in the other three unit electrode regions 5c ₁ , 5c ₂ , 5c _4.

In conclusion, in the divided electrode 5 that has undergone dielectric breakdown, the area ratio at which the capacitance forming function is lost is about one-fourth (the remaining about three-quarters remains as the effective electrode area). That is, in the case of the embodiment of the present invention, the effective electrode area disappearance rate in one divided electrode that has undergone dielectric breakdown corresponds to a decrease of about 50% as compared with the case of the conventional example. ..

Moreover, according to the present invention, since the unit electrode region is formed without additionally forming a new insulating slit, it is possible to avoid a decrease in the effective electrode area due to the formation of the insulating slit. Therefore, it is possible to suppress the decrease in the effective electrode area due to the increase in the insulating slit width due to the increase in voltage as much as possible, and to reduce the effective electrode area disappearance rate while improving the withstand voltage performance. Further, by providing a fuse in the middle of the second insulating slit, it is possible to prevent an increase in the fuse (high resistance part) and prevent the capacitor from increasing as compared with the case where the insulating slit is formed in the longitudinal direction of the film and the fuses are provided at both ends thereof. Fever can be suppressed.

As described above, according to the present embodiment, it is possible to improve the withstand voltage performance while suppressing the decrease in the effective electrode area and the loss of the capacitance forming function to improve the capacitor life.

〔Concrete example〕
Element specifications:
Capacity 150 μF
Rated voltage 1650 VDC
Film 5.5 μm
50 mm width The line width of the first insulating slit 4 and the second insulating slit 4b is 0.15 mm.

The dimensions of the second fuse 6b (opening width of the cut of the second insulating slit 4b) are expected to increase or decrease by ± 5% based on the dimensions of the first fuse 6 (1.5 mm). Is preferable.

The width dimension (arrangement pitch) of the subdivided small electrode 5b or the unit electrode region 5c in the film longitudinal direction X is 3 mm.

The line width of the insulation margin 8 is 3 mm.

A pair of linear insulating slits 4c, 4c adjacent to each other in the large area electrode row region A1 of the first row have a pitch of 24 mm, and a pair of linear insulating slits 4c, adjacent to each other in the large area electrode row region A2 of the second row. The pitch of 4c is 48 mm. Therefore, the number of segments (subdivided small electrodes 5b) in each of the regions A1 and A2 is 8 and 16.

Withstanding voltage (measures the change in capacitor element capacitance after 75 ° C., 1920 VDC, and 1000 hrs as a life test) and safety (counts the number of short circuits in the life test) using five specimens under the above conditions. As a result of evaluation, it was confirmed that both withstand voltage resistance and safety were improved compared to the conventional product.

The present invention is a technique for improving withstand voltage performance while improving capacitor life by suppressing a decrease in effective electrode area and thus a loss of capacitance forming function when clearing a metallized film capacitor when dielectric breakdown occurs. It is useful.

1 Metallic film 2 Dielectric film 3 Thin-film electrode 4 First insulation slit 4b Second insulation slit 5B Divided electrode
5c ₁ 1st unit electrode region
5c ₂ Second unit electrode region
5c ₃ Third unit electrode region
5c ₄ 4th unit electrode region
5b Subdivided small electrode
5b ₁ 1st (left side) subdivided small electrode
5b ₂ Second (right side) subdivided small electrode 6 First fuse 6b Second fuse A1, A2 Large area electrode row area B1, B2 Small area electrode row area X Film longitudinal direction Y Film width direction

Claims (3)

With a dielectric film in which the vapor deposition electrodes are formed on at least one side,
The vapor-deposited electrode is developed in a small area electrode row region developed in a relative small area division state along the film longitudinal direction of the dielectric and in a continuous state or a relative large area division state along the film longitudinal direction. The set with the large-area electrode row region to be formed is repeatedly arranged along the film width direction of the dielectric.
The small-area electrode row region is partitioned into each divided electrode by a continuous first insulating slit extending in the film width direction and having no break in the middle portion.
Wherein each of the divided electrodes,
It is electrically connected to the large area electrode row region at the end of the first insulating slit in the film width direction via the first fuse.
Further, it is partitioned into a pair of subdivided small electrodes facing each other in the film longitudinal direction by a second insulating slit extending in the film width direction at the intermediate portion in the film longitudinal direction.
The pair of subdivided small electrodes are electrically connected to each other via a second fuse at a cut in the middle of the second insulating slit.
Each subdivided small electrode is divided into a pair of unit electrodes adjacent areas in the width direction of the film, their pair of unit electrodes regions communicate with each other,
The second insulating slit has one portion and the other portion separated from each other with the second fuse, which is the cut, interposed therebetween.
Of the pair of subdivided small electrodes facing each other in the longitudinal direction of the film, the first subdivided small electrode on one side in the longitudinal direction of the film is one portion of the second insulating slit and one side in the longitudinal direction of the film. A first unit electrode region sandwiched between the first insulating slits located in, and the other portion of the second insulating slit and the first insulating slit located on one side in the longitudinal direction of the film. It is a second unit electrode region sandwiched between
Of the pair of subdivided small electrodes facing each other in the longitudinal direction of the film, the second subdivided small electrode on the other side in the longitudinal direction of the film is the one portion of the second insulating slit and the other side in the longitudinal direction of the film. A third unit electrode region sandwiched between the first insulating slits located in, and the other portion of the second insulating slit and the first insulating slit located on the other side in the longitudinal direction of the film. It is a fourth unit electrode region sandwiched between
A metallized film for a capacitor element, wherein each of the first to fourth unit electrode regions is electrically connected to the large area electrode row region via the first fuse. In the first insulating slit and the second insulating slit, the second insulating slit is arranged between each pair of the first insulating slits adjacent to each other in the film longitudinal direction, and the film length is formed. the first insulating slits are arranged between each other each pair of said second insulating slits adjacent in the direction, the one with the second insulating slit between the first insulating slit along the longitudinal direction of the film The metallized film for a capacitor element according to claim 1, which is alternately arranged in a skipped state. In a metallized film capacitor in which two metallized films for a capacitor element according to claim 1 or 2 are superposed to form a pair of metallized films.
A metallized film capacitor in which all of the large-area electrode row regions of one of the pair of metallized films face the subdivided small electrodes of the other metallized film.

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